body { 
  height: 100%;
  // background-color: #ebebeb;
}
.app {
  padding-top: 55px; 
  height: 600px;
  overflow: hidden;
  box-sizing: border-box; 
  background: #ebebeb; 
}

.links {
  display: flex;
  background: #fff;
  height: 50px;
  width: 100%; 
  position: absolute;
  top: 0; 
  align-items: center;  
  justify-content: space-around;
  a{
    background-color: #fff;
    border: 1px solid;
    padding: 3px 5px;
    margin: 3px; 
    text-decoration: none;
  }
}